Porous-hearth furnace.



110,839,064. 4 PATENTBD 0130.101900;

J. E. GRBENAWALT. P00000 111311111311 FURNAGE.

APRLICATION FILED MAR.27. 1005. 11131113111131111101A 24, 1906.

' 3 SHEET SHEET 1.

y I 2! Wn 2 No. 839,064. PATENTBD DEC. 1a, 1906.

J. E. lGREBMWALT.

PoRoUs HBARTH PURNAGB.

APPLxoATIoN FILED 111111.27, 1905. xmwwzn un. 24, 190e.

' a SHEETS-SHEET 2.

PATENTBD DBC. 18, 1906.

J. E'. GRBBNAWALT. PoRoUs HEARTH FURNAGB. APPLICATION FILED MAR. 27, 1905. RBNEWED APR. 24, 1906.

3 SHEETS-SHEET 3.

Y Sumava/ @2m-@wm l glp/wav (ke/4wd,

is f f porous-hearth furnaces of the general class To ,all"tchc'nt4 it concern.- [,Be it knoWIlt-hat I, JOHN E. GREENAWALT,

oF DENvR, COLOR-Ano. I

y '."PonOUs-HEARTH F'u'nNAcE.

a citizen of the United States, residingjin-the 1 cityand county of Denver and State, of Colo-` rado, haveinvented certain new and Im rovements in'Porous-Hearth Furnaces;

han' fI 'do declare lthe following to Vbe a full,

clear, and exact description of the invention,

' such `as willenable others skilled in the art I patent filed to" which .it l appertains to make and use the .I same,ref erencebeing had'to the accompanyingldrawings, and to the letters and figures of erence marked thereon, ofthis specifica-tion.

My invention relates 'to improvements in' which form a part set forthin rn application for United States ecember 27, 1901, Serial No.

l '87,510'. In my present invention the hearth proper is 'similar in construction tovthat illustratedand described in cation. g e

My improvements consist in providing means for passing air or gas from the furnace-chamber down through the bed of ore and through'the porous hearth into chambersv or compartments formed underneath the hearth, whereby the volatilized values contined inv the .fumes or gases may be Vsave The invention further embraces, in additionto the porous hearth and means for passing Iair r other gas or fumes downwardly through the bed of material-andl the hearth @the values contained inthe said'fumes orga'ses upon. which it rests, means for precipitating The invention further embraces the introduction of air or other gas'I through the top of the furnace into thechamber thereof above the bed of ore or other material lying upon the hearth, the said airor gas being i11- troduced at some distance from the ordinary sourceof heat or producer-gas delivered to the furnace for combustion urposes. air introduced to the top of) the furnace is `delivered thereto through a number of nozf y zles or conduits, whereby it is properly disv tributed and caused to mingle with the fuelgases, resulting in the production in an economical manner ofthe necessary heat for the purpose of roasting or otherwise ro erly treating the ore or other material) p aced upon the porous bed. v. y

In this specification the mechanism will be described with special reference to its use in K specification of Letters Patent.' v wwtion filed l{a1-cli 27, 1905. Renewed April 24,1908. Serial No. l318,101.

my aforesaid appli- This roastthe vo atilized precious' metal values 'contained in the fumes Withinthe furnace.

There are certain ores carrying the vprecious metals in such combinations; that when the orefis roasted aconsiderablepercentage of the gold and silver volatilizes in the form of fumes', and in the .ordinary furnace these valuable fumes mix with the products of combustion and dust of the furnace and pass into dust-chambers and the 4furnace-stack. Experience has shown that it is a difficult matter to completely precipitate and recover these values a ter they are mixed or mingled with the large volume of fuel-gases and Vdust arising from the ore or other material under treatment. In my invention byl reason ofl a downward suction through the hearth these fumes are drawn downwardly through the hearth and deposited in a condensing-chamber ina comparatively pure state. By this the gases are concentrated in a small current from lthe furnace proper.

Having briefly out ined my improved construction, as well as the function it is intended to perform, I will proceed to describe the same in detail, reference being made to the accompanying drawings, in which is illustrated an embodiment thereof.

In the drawings-` Figure 1 is a cross-section of the furnace, the condensing-chamber being shown in vertical section. Fig. 2 is a top plan view of the furnace, shown on a smaller scale, the 'ilues for the introduction of the heat or fuel-gases at one end of the furnace and for the escape of the waste gases at the olpposite extremity of the furnace being s own in horizontal section. Fig. 3 is a cen-v tral longitudinal section taken through the furnace on the same scale as 2.

l The same reference characters indicate the same parts in all the views.

When ore is roasted upon a orous bed of the character illustrated 1n the rawings, rabor oxidizing ores and the of' arrangement the valuable constituentsvofv A`patriarcal;nec. 18,190@ l A i IOO bling mechanism is necessary for the urpose of stirring the ore and advancing it on itudinally on the hearth, whereby new su aces of the ore are constantly exposed to the ac- In the furnace illustrated ment Iwill be required. To this end I have shown sprocket-wheels at each end of the furnace, which the endless rabble-chains (not shown) would engage in actual practice. In the drawings the ore lto be roasted or treated is supposed to be placed upon the porous bed 1. This bed constitutes the hearth of the furnace, and the ore is rabbled over this hearth by suitable mechanical rabbles, (not shown,) but heretofore briefly described. The furnace is preferably heated by means of producer-gas introduced throu h the flue 2 and is sup lied at intervals Wit air through a series o pipes 3, having nozzles passing through the top of the furnace, enough pipes and nozzles being employed to ive the desired or necessary distribution, t e air being supplied to the pipes 3 from a main pr J `13, connected with any suitable source of airsupply. The air so introduced mingles with the producer-gas, furnishing the necessary heat for the roasting operation, and the waste gases pass through the ue 4 to the chimney or'stack. Directly underneath the porous hearth or bed are large chambers a and b, whichare divided by suitable crosswalls into compartments, so that the volume of gases drawn through.. the hearth may be controlled and re ated in the different compartments. T e hearth .is constructed upon a series of arches in the formof solid rings 5, having spaces C of about four inches in width between them. These spaces-are covered by a course of bricks H, set on. edge and about one inch apart, leaving intermediate spaces E communicating with the spaces C between.the arches 5. Upon these bricks is placed a layer of coarse gravel or ore F and then a layer of smaller pieces until the last four inches, which consist of sand or fine ore.

The gases are drawn throu h the ore-bed and the porous hearth into t e chambers a and b and thence through pipes 7 into condensing-chambers 8 by the suction created by means of a steam-jet pipe 9 entering each pipe 7 or other suitable suction-producing apparatus. Each chamber 8 is provided with a number of condensing-compartments 21, formed in its lower ortion, while its .upper portion is filled withJ brick-checker-work 22,` constructed substantially las shown in the drawings, whereby the fumes may pass upwardly therethrou h and the condensing- Water iiow downwar ly to the 'reservoirs 19 in the bottom of each chamber, the said reservoirs being supplied by the water from the perforated pipes 10, mounted in the top of the condensing-chamber. The condensed or recipitated values may be easily recovered om the reservoirs 19.

The waste or unconsumed gases pass fromv each condensing-chamber through a pipe 23 into a main conduit 24, (see 2,) which leads to a suitable stack. (N ot shown.) As shown in the drawings, referring to 2,

yparts 27.

`as they travel above the furnace.

each condensing-chamber is provided with a number of branch water-pipes 10, connected on the ore between the sides 27 of the hearth,

while the endless chains carrying the rabbles rest upon tracks 28, located outside of the Mounted on top of the furnace are tracks 29 for the support of the rabble-chains These tracks 29 are in vertical alinement with the tracks 28 within the furnace.

By incorporating a suitable catalyticy agent-as platinized asbestos, ferric oXid, &c.-in the porous bed a considerable proportion of the sulfurous anhydrid contained in the ore-fumes ma be cheaply and economically converted lnto sulfuric anhydrid, and thus into sulfuric acid in the condensing chamber or chambers.

Having thus described my invention, what I claim is- 1. In a furnace for treating ore or other material, the combination of a porous bed or hearth, and means for passing air or gas downwardly through the material and the hearth upon which 1t rests.

2. In a furnace of the class described, the combination of a porous hearth and means for passing air or gas from within the furnace downwardly through the percus hearth, and means for condensing valuable volatilized elements carried downwardly with the gas.

3. In a furnace, the combination of a orous hearth having incorporated therein a catalytic agent, means for passing air or furnace-gases downwardly through the ore and through the porous hearth or bed.

4. n a roasting-furnace, the combination of a crous hearth having incorporated in it a catalytic agent, means for passing air or furnace-gases downwardly through the ore and through the porous hearth, and means for condensing the volatilized values carried by the fumes or gases, substantially as described. 5. In an apparatus of the class described, the combination of a roasting-furnace'provided with a porous hearth, a chamber lo cated beneath the porous hearth, and means for passing air or other gases from the furnace downwardly through the hearth into the said chamber.

6. In an apparatus of the class described, the combination of a furnace provided with va porous hearth, a chamber located beneath the porous hearth and composed of a number of intercommunicating compartments, means for passing air, gases or furnace-fumes downwardly through the hearth into the chamber from beneath, and a condensingchamber IOO IIS

connected with the'chamber beneath the l r 5 porous hearth, a chamber beneath the furnace, means for passing air, gases o r fumes from the furnace downwardly through the hearth into the chamber belowl the same, a condensing --chamber communicating with lo the chamber beneath the hearth, and means for supplying the condensing-chamber with the necessary water for condensing purposes.

8. In a roasting-furnace, the combination l of a porous hearth, means for passing air in distrlbuted Volume through-thetop of the 15 furnace into the roasting-chamber, and means for assing air, gases or furnace-fumes downwardfy through vthe porous hearth for the purpose set fort In testimony whereof I affix my signature o in presence vof two witnesses.

JOHN GREENAWALT.

Witnesses: A y .DENA NELSON,- A. J. OBRIEN. 

